The emails hit the inboxes of 23andMe members earlier this year. While their customers had grown accustomed to periodic updates about their health-risk indicators and genetic traits, this particular email was different from the rest: “We’re excited to offer you a chance to join our first ever Weight Loss Intervention Study,” it said.

This “massive” undertaking by 23andMe garnered headlines around the world. Their plan was to recruit 100,000 members who had consented to participate in research and divide them for 12 weeks among one of three diets: one that curtails carbs, one that increases fiber and reduces intake of animal fat, and one that maintains a normal diet but adds exercise.

 “Our research team is hoping that from the data collected from this intervention study, we’ll be able to learn whether there are genetic, lifestyle or other reasons why some individuals lose weight or respond better to certain weight loss interventions, regardless of which diet or exercise plan they follow,” Liana Del Gobbo, PhD, lead scientist at 23andMe, told us in an email interview.

Founded in 2006, the Mountain View, Calif., company is a pioneer in the field of “spit in a tube, send it back, and we’ll tell you cool things about your genome and ancestry.” And there are indeed plenty of cool things to discover when you take a spiraling ride down your double helix, such as carrier status for genetic diseases, health risks and other traits, as well as ancestry information.

One of the most intriguing fields of inquiry is nutrigenomics, also referred to as personalized nutrition. Previous research has looked at relationships between genetics and health. One notable example was a 2015 study of 800 people by the Weizmann Institute of Science in Israel that helped researchers develop an algorithm they say can predict changes in blood sugar levels after meals, which was then licensed to a company called DayTwo to create personalized nutrition plans.

“This is an example of converting landmark research linking nutrition, health conditions — in this case, glycemic response — the microbiome and machine learning into practical applications,” said Ali Webster, PhD, RD, associate director of nutrition communications at the IFIC Foundation.

But research like the weight loss study by 23andMe can draw upon databases that are orders of magnitude bigger than 800 subjects, holding open the possibility of more relevant, detailed and useful results.

“Based on the data we collect and analyze from the intervention study, we’d like to better understand the genetic, demographic, psychosocial, and behavioral characteristics that predict weight loss success overall, and on different lifestyle interventions,” Del Gobbo said.

“We also hope to demonstrate that our platform is able to carry out large-scale clinical trials of the type normally performed by research universities or drug companies.”

The concept of huge corporate or governmental databases to which we voluntarily hand over the keys to our genetic kingdoms has understandably touched off debates over issues like privacy and ethics. But as the technology and safeguards mature, their potential for the greater good — especially public health — is coming into sharper focus, with mounting arguments about how the benefits outweigh the potential drawbacks.

Still, the experts say we need to temper our expectations. No database in the world can substitute for tried-and-true eating patterns — diets rich in fruits, vegetables, whole grains and lean protein, along with controlled intake of overall calories in check. The consensus is that are a lot more questions to ask, and we’re only now on the steep end of a daunting learning curve.

“The main drawback is this: There’s still a huge gap between what we know about the relationship between our eating patterns and our genes, and vice versa, and the interplay with our behaviors and environments,” Webster said. “Drawing conclusions too quickly is dangerous and likely to be incorrect.”

For scientists like Webster, evidence-based personalized nutrition plans are the Holy Grail of nutrigenomics. Several direct-to-consumer personalized nutrition services already are on the market, but the science isn’t conclusive enough for many health professionals to recommend any of them in particular. Instead, they recommend that consumers proceed carefully and skeptically.

However, if you do decide to sign up for one of those programs, read the fine print for disclaimers of uncertainty or statements that their nutrition recommendations lack definitive evidence. Talk to your health care provider or a Registered Dietitian to see how one of these genetic tests could fit into your healthcare plan.

The day when our diets are perfectly tailored to our own genomes is tantalizingly close. Until then, the best advice you could heed — beyond a basic, healthy eating pattern — is caveat emptor.